In the prior art ink pens have been known which contain ink and eradicator. The eradicator bleaches the ink. However, the ink thus eradicated either reappears after a time due to oxidation of the eradicator or the eradicator is so effective that in the area where it has been used, the same ink cannot be reapplied. Thus normally one, two or three pens are required in order to have a reinkable system. The first ink is applied as fresh ink, another pen or the opposite side of the same pen, eradicates the first ink. Then a second pen is required in order to cover up the eradicated ink and make a new ink mark, but with a different ink.